> **PROTOTYPE:** a suggestion, not an official CIAAW or IUPAC page. Official values are at [ciaaw.org](https://ciaaw.org).

# molybdenum

| Property | Value |
| --- | --- |
| Symbol | Mo |
| Atomic number | 42 |
| IRI | `https://hendrikborgelt.github.io/Draft_for_IUPAC_CIAAW-Isotopic-Abundances-and-Atomic-Weights/elements/Molybdenum` |
| Wikidata | [Q1053](https://www.wikidata.org/wiki/Q1053) |

## Standard atomic weight

| Value | Year | Source | Status | Declaration |
| --- | --- | --- | --- | --- |
| 95.95(1) | 2013 | [10.1515/pac-2015-0305](https://doi.org/10.1515/pac-2015-0305) | Current | [`AW-Mo-standard`](../id/AW-Mo-standard.md) |
| 95.96(2) | 2007 | [10.1351/PAC-REP-09-08-03](https://doi.org/10.1351/PAC-REP-09-08-03) | Deprecated, see [`AW-Mo-standard`](../id/AW-Mo-standard.md) | [`AW-Mo-standard-2007`](../id/AW-Mo-standard-2007.md) |
| 95.94(2) | 2001 | [10.1351/pac200375081107](https://doi.org/10.1351/pac200375081107) | Deprecated, see [`AW-Mo-standard-2007`](../id/AW-Mo-standard-2007.md) | [`AW-Mo-standard-2001`](../id/AW-Mo-standard-2001.md) |
| 95.94(1) | 1975 | [10.1351/pac197647010075](https://doi.org/10.1351/pac197647010075) | Deprecated, see [`AW-Mo-standard-2001`](../id/AW-Mo-standard-2001.md) | [`AW-Mo-standard-1975`](../id/AW-Mo-standard-1975.md) |
| 95.94(3) | 1969 | [10.1351/pac197021010091](https://doi.org/10.1351/pac197021010091) | Deprecated, see [`AW-Mo-standard-1975`](../id/AW-Mo-standard-1975.md) | [`AW-Mo-standard-1969`](../id/AW-Mo-standard-1969.md) |
| 95.94 | 1961 | [10.1021/ja00881a001](https://doi.org/10.1021/ja00881a001) | Deprecated, see [`AW-Mo-standard-1969`](../id/AW-Mo-standard-1969.md) | [`AW-Mo-standard-1961`](../id/AW-Mo-standard-1961.md) |
| 95.95 | 1938 | [10.1039/JR9380001101](https://doi.org/10.1039/JR9380001101) | Deprecated, see [`AW-Mo-standard-1961`](../id/AW-Mo-standard-1961.md) | [`AW-Mo-standard-1938`](../id/AW-Mo-standard-1938.md) |
| 96 | 1902 | [10.1007/BF01370337](https://doi.org/10.1007/BF01370337) | Deprecated, see [`AW-Mo-standard-1938`](../id/AW-Mo-standard-1938.md) | [`AW-Mo-standard-1902`](../id/AW-Mo-standard-1902.md) |

Notes: [g](#note-g)

## Isotopes

| A | Representative isotopic composition | Year | Source | Declaration | ChEBI | Wikidata |
| --- | --- | --- | --- | --- | --- | --- |
| [92](../id/Mo-92.md) | 0.146 49(106) | — | — | [`Abundance-Mo92`](../id/Abundance-Mo92.md) | — | [Q4499982](https://www.wikidata.org/wiki/Q4499982) |
| [94](../id/Mo-94.md) | 0.091 87(33) | — | — | [`Abundance-Mo94`](../id/Abundance-Mo94.md) | — | [Q13860694](https://www.wikidata.org/wiki/Q13860694) |
| [95](../id/Mo-95.md) | 0.158 73(30) | — | — | [`Abundance-Mo95`](../id/Abundance-Mo95.md) | — | [Q3355387](https://www.wikidata.org/wiki/Q3355387) |
| [96](../id/Mo-96.md) | 0.166 73(8) | — | — | [`Abundance-Mo96`](../id/Abundance-Mo96.md) | — | [Q1928853](https://www.wikidata.org/wiki/Q1928853) |
| [97](../id/Mo-97.md) | 0.095 82(15) | — | — | [`Abundance-Mo97`](../id/Abundance-Mo97.md) | — | [Q2690215](https://www.wikidata.org/wiki/Q2690215) |
| [98](../id/Mo-98.md) | 0.242 92(80) | — | — | [`Abundance-Mo98`](../id/Abundance-Mo98.md) | — | [Q2019439](https://www.wikidata.org/wiki/Q2019439) |
| [100](../id/Mo-100.md) | 0.097 44(65) | — | — | [`Abundance-Mo100`](../id/Abundance-Mo100.md) | — | [Q4689619](https://www.wikidata.org/wiki/Q4689619) |

Notes: [g](#note-g)

## Notes

<a id="note-g"></a>**g** Geological and biological materials are known in which the element has an isotopic composition outside the limits for normal material. The difference between the atomic weight of the element in such materials and that given in the table may exceed the stated uncertainty.

## Bibliography

<div class="csl-bib-body">
<div class="csl-entry">(1976). <i>Pure and Applied Chemistry</i>, <i>47</i>(1), 75–96. https://doi.org/10.1351/pac197647010075 <a href="https://doi.org/10.1351/pac197647010075">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1351/pac197647010075">Scholia</a></div>
<div class="csl-entry">Atomic weights of the elements 1969. (1970). <i>Pure and Applied Chemistry</i>, <i>21</i>(1), 91–108. https://doi.org/10.1351/pac197021010091 <a href="https://doi.org/10.1351/pac197021010091">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1351/pac197021010091">Scholia</a></div>
<div class="csl-entry">Baxter, G. P., Hönigschmid, O., &#38; Lebeau, P. (1938). Eighth Report of the Committee on Atomic Weights of the International Union of Chemistry. <i>J. Chem. Soc.</i>, <i>0</i>(0), 1101–1109. https://doi.org/10.1039/jr9380001101 <a href="https://doi.org/10.1039/JR9380001101">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1039/JR9380001101">Scholia</a></div>
<div class="csl-entry">Cameron, A. E., &#38; Wichers, Edward. (1962). <b>Report of the International Commission on Atomic Weights<sup>*</sup>(1961)</b>. <i>Journal of the American Chemical Society</i>, <i>84</i>(22), 4175–4197. https://doi.org/10.1021/ja00881a001 <a href="https://doi.org/10.1021/ja00881a001">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1021/ja00881a001">Scholia</a></div>
<div class="csl-entry">Loss, R. D. (2003). Atomic weights of the elements 2001 (IUPAC Technical Report). <i>Pure and Applied Chemistry</i>, <i>75</i>(8), 1107–1122. https://doi.org/10.1351/pac200375081107 <a href="https://doi.org/10.1351/pac200375081107">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1351/pac200375081107">Scholia</a></div>
<div class="csl-entry">Meija, J., Coplen, T. B., Berglund, M., Brand, W. A., De Bièvre, P., Gröning, M., Holden, N. E., Irrgeher, J., Loss, R. D., Walczyk, T., &#38; Prohaska, T. (2016). Atomic weights of the elements 2013 (IUPAC Technical Report). <i>Pure and Applied Chemistry</i>, <i>88</i>(3), 265–291. https://doi.org/10.1515/pac-2015-0305 <a href="https://doi.org/10.1515/pac-2015-0305">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1515/pac-2015-0305">Scholia</a></div>
<div class="csl-entry">Richards, Baxter, Hinrichsen, Köthner, P., &#38; Pellini, S. (1902). Zur Festsetzung der Atomgewichte. <i>Fresenius’ Zeitschrift für analytische Chemie</i>, <i>41</i>(2), 139–140. https://doi.org/10.1007/bf01370337 <a href="https://doi.org/10.1007/BF01370337">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1007/BF01370337">Scholia</a></div>
<div class="csl-entry">Wieser, M. E., &#38; Berglund, M. (2009). Atomic weights of the elements 2007 (IUPAC Technical Report). <i>Pure and Applied Chemistry</i>, <i>81</i>(11), 2131–2156. https://doi.org/10.1351/pac-rep-09-08-03 <a href="https://doi.org/10.1351/PAC-REP-09-08-03">CrossRef</a> <a href="https://qlever.scholia.wiki/doi/10.1351/PAC-REP-09-08-03">Scholia</a></div>
</div>

## Turtle

This resource as a file: [Molybdenum.ttl](Molybdenum.ttl)

```turtle
# Prototype: a suggestion, not an official CIAAW or IUPAC record. Official values are at https://ciaaw.org

@prefix adms: <http://www.w3.org/ns/adms#> .
@prefix chemrof: <https://w3id.org/chemrof/> .
@prefix ciaaw: <https://hendrikborgelt.github.io/Draft_for_IUPAC_CIAAW-Isotopic-Abundances-and-Atomic-Weights/ciaaw-draft#> .
@prefix ciaaw_draft: <https://hendrikborgelt.github.io/Draft_for_IUPAC_CIAAW-Isotopic-Abundances-and-Atomic-Weights/id/> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix element: <https://hendrikborgelt.github.io/Draft_for_IUPAC_CIAAW-Isotopic-Abundances-and-Atomic-Weights/elements/> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix qudt: <http://qudt.org/schema/qudt/> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix unit: <http://qudt.org/vocab/unit/> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

ciaaw:note-g a ciaaw:Footnote ;
    skos:definition "Geological and biological materials are known in which the element has an isotopic composition outside the limits for normal material. The difference between the atomic weight of the element in such materials and that given in the table may exceed the stated uncertainty."@en ;
    skos:notation "g" .

ciaaw_draft:AW-Mo-standard-1902 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Mo-standard-1938 ;
    dcterms:issued "1902"^^xsd:gYear ;
    dcterms:source <https://doi.org/10.1007/BF01370337> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Molybdenum ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 96.0 ] .

ciaaw_draft:AW-Mo-standard a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:issued "2013"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Mo-standard-2007 ;
    dcterms:source <https://doi.org/10.1515/pac-2015-0305> ;
    ciaaw:footnote ciaaw:note-g ;
    ciaaw:ofElement element:Molybdenum ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 95.95 ;
            qudt:standardUncertainty 0.01 ;
            ciaaw:significantFigures 4 ;
            ciaaw:significantFiguresUncertainty 1 ] .

ciaaw_draft:AW-Mo-standard-1938 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Mo-standard-1961 ;
    dcterms:issued "1938"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Mo-standard-1902 ;
    dcterms:source <https://doi.org/10.1039/JR9380001101> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Molybdenum ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 95.95 ] .

ciaaw_draft:AW-Mo-standard-1961 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Mo-standard-1969 ;
    dcterms:issued "1961"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Mo-standard-1938 ;
    dcterms:source <https://doi.org/10.1021/ja00881a001> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Molybdenum ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 95.94 ] .

ciaaw_draft:AW-Mo-standard-1969 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Mo-standard-1975 ;
    dcterms:issued "1969"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Mo-standard-1961 ;
    dcterms:source <https://doi.org/10.1351/pac197021010091> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Molybdenum ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 95.94 ;
            qudt:standardUncertainty 0.03 ;
            ciaaw:significantFigures 4 ;
            ciaaw:significantFiguresUncertainty 1 ] .

ciaaw_draft:AW-Mo-standard-1975 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Mo-standard-2001 ;
    dcterms:issued "1975"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Mo-standard-1969 ;
    dcterms:source <https://doi.org/10.1351/pac197647010075> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Molybdenum ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 95.94 ;
            qudt:standardUncertainty 0.01 ;
            ciaaw:significantFigures 4 ;
            ciaaw:significantFiguresUncertainty 1 ] .

ciaaw_draft:AW-Mo-standard-2001 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Mo-standard-2007 ;
    dcterms:issued "2001"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Mo-standard-1975 ;
    dcterms:source <https://doi.org/10.1351/pac200375081107> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Molybdenum ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 95.94 ;
            qudt:standardUncertainty 0.02 ;
            ciaaw:significantFigures 4 ;
            ciaaw:significantFiguresUncertainty 1 ] .

ciaaw_draft:AW-Mo-standard-2007 a ciaaw:StandardAtomicWeightDeclaration ;
    dcterms:isReplacedBy ciaaw_draft:AW-Mo-standard ;
    dcterms:issued "2007"^^xsd:gYear ;
    dcterms:replaces ciaaw_draft:AW-Mo-standard-2001 ;
    dcterms:source <https://doi.org/10.1351/PAC-REP-09-08-03> ;
    owl:deprecated true ;
    adms:status <http://purl.org/adms/status/Deprecated> ;
    ciaaw:ofElement element:Molybdenum ;
    ciaaw:value [ a qudt:QuantityValue ;
            qudt:hasUnit unit:UNITLESS ;
            qudt:numericValue 95.96 ;
            qudt:standardUncertainty 0.02 ;
            ciaaw:significantFigures 4 ;
            ciaaw:significantFiguresUncertainty 1 ] .

element:Molybdenum a chemrof:ChemicalElement ;
    rdfs:label "molybdenum"@en ;
    ciaaw:currentStandardAtomicWeight ciaaw_draft:AW-Mo-standard ;
    ciaaw:hasDeclaration ciaaw_draft:AW-Mo-standard,
        ciaaw_draft:AW-Mo-standard-1902,
        ciaaw_draft:AW-Mo-standard-1938,
        ciaaw_draft:AW-Mo-standard-1961,
        ciaaw_draft:AW-Mo-standard-1969,
        ciaaw_draft:AW-Mo-standard-1975,
        ciaaw_draft:AW-Mo-standard-2001,
        ciaaw_draft:AW-Mo-standard-2007 ;
    ciaaw:hasIsotope ciaaw_draft:Mo-100,
        ciaaw_draft:Mo-92,
        ciaaw_draft:Mo-94,
        ciaaw_draft:Mo-95,
        ciaaw_draft:Mo-96,
        ciaaw_draft:Mo-97,
        ciaaw_draft:Mo-98 ;
    ciaaw:standardAtomicWeightUncertainty 0.01 ;
    ciaaw:standardAtomicWeightValue 95.95 ;
    chemrof:atomic_number 42 ;
    chemrof:symbol "Mo" .
```

[All atomic weights](../atomic-weights.md) · [All isotopic abundances](../isotopic-abundances.md)